The present invention relates to video signal processing systems that have optional xe2x80x9cV-Chipxe2x80x9d ratings control (RC), optional auxiliary information display such as closed captioning (CC) display, and the option of simultaneously displaying a main picture (or image) and one or more auxiliary pictures (or images).
Video signal processing apparatus which process and produce a signal suitable for coupling to a display device for producing a display having, at the option of the viewer, main and auxiliary images, i.e., multi-image display, are well known. As used herein, the term xe2x80x9cvideo signal processing apparatusxe2x80x9d or xe2x80x9cvideo signal processing systemxe2x80x9d is intended to encompass various types of video signal processing devices including, but not limited to, television signal processing devices that may or may not include a display device. Examples of such devices include television sets, television receivers, direct broadcast satellite (DBS) signal receivers, and video cassette recorders (VCR). A displayed image produced in response to activating a multi-image option includes the auxiliary image either within, outside or beside the main image. For example, certain television receivers include a picture-in-picture (xe2x80x9cpix-in-pixxe2x80x9d or xe2x80x9cPiPxe2x80x9d) feature that, when activated, produces an image signal representing both a main image region and a smaller auxiliary image region within the main image region.
With regard to closed captioning and ratings control, all television receivers larger than 13xe2x80x3 in size, which includes virtually all multi-image display-capable receivers sold in the U.S., are required to include both CC decoding capability and V-Chip RC capability. As described in more detail below, CC and RC capability are provided by decoding auxiliary information included in a television signal. For example, auxiliary information may be included in the vertical blanking interval (VBI) of an analog television signal such as an NTSC signal. In a digital television signal, such as an HDTV signal which includes packets of digital data, auxiliary information may be included in certain packets of digital data, e.g., packets having a particular packet identifier. The auxiliary information included in a television signal comprises various types of data including CC data and Extended Data Services (XDS) data. XDS data provides various types of information such as program rating information. The ratings information included in XDS data can be decoded and used to provide V-Chip RC capability. Both CC and XDS data are described in detail in standard EIA-608 from the Electronics Industries Association.
Other systems for providing auxiliary information, such as captioning and rating information, are known. For example, teletext systems in use in Europe provide such information.
In the U.S. V-Chip rating control system, V-Chip ratings control (RC) can be activated or deactivated by a viewer who has the proper authorization (hereinafter referred to as xe2x80x9cparentxe2x80x9d). When activated by the parent, the processor within the receiver utilizes a xe2x80x9cstripperxe2x80x9d which functions to slice, or extract, auxiliary information, and process ratings information contained in the television signal. When the ratings information exceeds the value elected by the authorized viewer, the processor is designed to blank the screen and mute the audio portion of the broadcast. For television receivers which also have multi-image display capability, the receiver must provide RC if both main and auxiliary pictures are displayed and the parent has activated RC. A television receiver that provides RC permits a user to prevent certain programs and/or scenes from being viewed and heard based on the content of the program/scenes. For example, a user might specify that programs and/or scenes including violent subject matter should be excluded. Alternatively, a user can specify a rating limit, such as PG-13, and programs and scenes exceeding that limit (e.g., R and X rated programs) could not be viewed or heard. By decoding program content information included in data such as XDS data, a television receiver containing the stripper can slice information from the VBI to determine the content and rating of television programs and scenes and can compare the content and rating to the limits set by a user. For those programs and scenes that exceed the specified limits, the video display is modified, e.g., blanked, and the audio is muted. In addition, the receiver may display a message indicating the reason for the interrupted reception and the expected duration of the interruption (e.g., SCENE EXCEEDS CONTENT LIMIT). The parent may also deactivate the V-chip ratings control by choosing to permit any level of broadcast to be displayed; in such case no stripping by a data slicer takes place.
CC data are also included in the VBI of standard television broadcasts, and are necessary for use by hearing impaired persons. For most viewers, CC is not needed and so television receivers provide means to toggle the CC display function on or off. A NTSC (National Television Standards Committee) television signal will include two bytes of closed captioning data during the latter half of each occurrence of line 21 of field 1. CC data may be decoded and displayed to provide a visible text representation of a television program""s audio content. Additional CC data and other types of auxiliary information, such as extended data services information (XDS), may be included in other line intervals such as line 21 of field 2.
In the case when the CC display option has been enabled and the parent has elected to activate the RC option, a single data slicer may be used for both functions by designing it to rapidly cycle back and forth between stripping CC and RC data; in such case it is usually necessary to design the cycles to be every two seconds, approximately, with appropriate timeouts if no data is received, in order to have effective CC processing and RC. In such situations, a problem has arisen for situations where the viewer also wishes to display both main and auxiliary images such as when a PiP or PoP feature is activated.
Prior to this invention, the conventional view has been that a second data slicer, which is a relatively expensive hardware item, would be needed to effectively handle both RC and CC functions for multiple broadcasts when V-Chip was legally mandated since CC data is received continuously and a single slicer could not be switched away to receive RC data, or else characters would be dropped from the CC.
In one aspect the invention comprises a method for operating a video signal processing system for producing an output signal suitable for coupling to a display device for producing a displayed image, and having the option of producing the output signal to represent a main picture and one or more auxiliary pictures (AP), ratings control (RC) capability which includes means for an authorized person to limit the display of programs having ratings beyond a selected level, and auxiliary information (AI) processing capability which includes means for a viewer to choose to display auxiliary information comprising closed captioning along with a picture, and a single stripper for extracting auxiliary data from a portion of one or more video signals comprising using the single stripper to process RC information for both the main picture and the auxiliary picture when the RC option has been invoked by cycling between main and auxiliary; and disabling the AP capability when the auxiliary information display option has been enabled.
In another aspect the invention comprises a video signal processing system for producing an output signal suitable for coupling to a display device for producing a displayed image having capability of receiving main and auxiliary video signals and, at the option of the viewer, displaying the signals simultaneously; a decoder for extracting and decoding coded ratings control data and closed captioning data multiplexed into the video signals; and one or more processors for: activating or deactivating closed captioning processing at the option of the viewer; activating and setting a level of ratings control processing at the option of an authorized person; rapidly cycling the decoder between extracting ratings control data and closed captioning data, when both are activated, for a single video signal; or to rapidly cycle the decoder between extracting ratings control for main and auxiliary video signals when simultaneous display is activated; and to automatically disable simultaneous displaying and thereupon display only main video signal when closed captioning is activated.
In another aspect, the invention comprises apparatus for processing and displaying a main television signal and optionally displaying a second television signal comprising a display device; a control device for optionally processing ratings control information contained in each displayed video signal and for optionally processing auxiliary information comprising captioning within a displayed television signal; a single device to strip ratings control information when ratings control option is invoked and to strip auxiliary information when auxiliary information is invoked; a processor to rapidly cycle the single device between stripping ratings control information between each of the main and auxiliary signals when ratings control option is invoked, and to disable the auxiliary signal option when auxiliary information display option is invoked.